To produce a generator by stacking separators and solid oxide fuel cells alternately, it is necessary to supply a gas between a separator and the single cell so that fuel or oxidizing gas is supplied to the electrodes of the single cell. At the same time, the single cell and the separator must be electrically connected in series by inserting an electrically conductive connecting member between the separator and single cell. When such connecting member is located in, for example, a fuel gas passage, it must be chemically stable in a reductive fuel gas environment at an operating temperature of the single cell. Further, there must be a gap which the fuel gas is passed. For such reasons, so-called nickel felt has been commonly used as the connecting member in the fuel gas passage.
However, permeability is reduced due to the deformation and/or shrinkage of nickel felt under pressure, so that the efficiency of generation tends to be lowered. The applicant has therefore disclosed that a metal mesh is embossed to form protrusions and the mesh is used as a conductive connector in Japanese Patent publication No. 2003-163016A. According to such conductive connector, it is possible to assure the permeability and make a load onto an electrochemical cell uniform even when the electrochemical cell is pressurized to assure the conductance.
FIG. 8 is a plan view showing a conductive connecting member 31 made of a mesh, disclosed in Japanese Patent publication No. 2003-163016A. The mesh 31 is obtained by knitting many conductive wires 32 so that many loops (spacings) 33 and 33A are formed among the many wires 32. The mesh 31 has a shape of a flat plate before giving emboss shape. Emboss-shaped portions 31b are formed at predetermined positions of the mesh 31. 31a represents a non-emboss-shaped portion maintaining the shape before giving the emboss shape. 33A represents loops in the emboss-shaped portion 31b. The loop 33A is curved compared with the shape of the loop 33.
The emboss-shaped portion 31b is protruded over one face of the mesh 31 with respect to the central plane of the mesh before giving the emboss shape. A space is thus formed in the side of back face of the emboss-shaped portion 31b. The shape and depth of the space is decided depending on the shape and height of the emboss-shaped portion.